Method of mining.



W. GRIFFITH. "wf "Apt/"wf METHOD 0F MINING. APPLIUATION FILED 111111.11, 1911.

Patented sep1.26,1911.

Cttornegs W. GRIFFITH.

METHOD or MINING.

APPLICATION FILED MAB.6, 1911.

1,004,418. Patented sept. 26, 1911.

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APPLIOATION FILED MAB. e, 1911.

M LA 0G )i O w N witnesses PATENT ornion.

WILLIAM GRIFFITH, OF WEST PITTSTON, PENNSYLVANIA.

METHOD OF MINING.

To all whom it may concern.'

Be it known 'that I, VILLIAM GRIFFITH, a citizen of the United States, residing at Test Pittston, in the county of Luzerne and State of Pennsylvania, have invented certain new and useful Improvements in Methods of Mining; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which itappertains to make and use the same.

This invention relates to an improved method of supporting or assisting in supporting a mine of ahy kind, including metal and ore mines.

The object in view is to provide a safe and cheap method of supporting or assisting in supporting the roofs of mines: first, to prevent the sudden collapse of the roof of the mine in places where the surface carries valuable improvements; v second, to provide means for the safe supporting of the roof during the prosecution of the second mining or the removal of the ordinary supporting pillars; and, third, to provide a safe method by which the roof may be supported and all the coal or other matter being mined may be secured during the first mining.

In the accompanying` drawings: Figure 1 is a longitudinal sectionalview showing a plan of a horizontal mine. Fig. 2 is a section through Fig.- 1 on line 2 2. Fig. 3 1s a section through Fig. l on line 3 3. Fig. 4 is a section through Fig. l on line` 4 4. Fig. 5 is a sectional view through a mine showinga plan of a pitching vein. Fig. 6 is a section through Fig. 5 on line 6 6.

In mining bedded or stratified deposits of metal or coal one general plan or system is used with variations. In mining coal the usual system in the United States is what is known as the. room and pillar system. This method of mining is varied somewhat necessarily on account of the disposition of the coal veins in the rock for permitting mining on flat or horizontal veins, and in pitching veins. VThe mining of flat or horizontal veins by the ordinary method contemplates the sorting of the coal from the refuse inthe room or part of the mine where it is removed froln its natural bed, and the refuse material, such as slate, bony coal, fire clay, and rock, is left in the room, and the coal is loaded in the cars and `taken out. In cases where coal occurs in such a steep pitch that the loose material will slide down and not Specification' of Letters Patent.

Application filed March 6, 1911.

Patented Sept. 26, 1911.

Serial No. 612,668.

remain where deposited it is necessary to re move all of the mined matter loosened by the mining operation, including coal and refuse matter, which coal and refuse matter must be sorted after having reached the surface.

In mining coal according to the present method approximately one-third of the coal in the veins is left in the mines to support the roof. In some instances other methods are used where all of the coal is taken out and the roof is purposely allowed to fall, and in other instances foreign matter, as stone, sand, and the like, is brought into the mine, and the mine is filled therewith as fast as the coal is removed, so as to prevent the `roof from falling.

This invention is intended to obviate as far as possible any injury or breaking down of any property on the surface of the ground, and at the same time to render available for shipment larger quantities of coal from a given coal field than is now possible to mine without endangering the lives of the miners or life and property on the surface of the ground.

The process or method consists briefly in blasting upA the floor which is usually rock, or blasting down the rock roof of the mine, or blasting up the floor and the roof directly over it, allowing the debris of the blasting to remain where it falls thus taking advantage of the well known characteristics of blasted rock, that it occupies considerable more space than when in the solid condition. Preferably the fioor is first blasted up and caused to fill approximately half of the room or opening, that is, not only to fill the space from'which it was blasted, but also to cause a pile of blasted rock to occupy approximately half of the vertical space of the room, and then a sufficient part of the rock roof is blasted for filling the remainder of the space. It will be noted that the blasted rock remains at the point blasted, and is not moved from one place to the other, but is always blasted wherever wanted, and in the desired quantities. The debris from the blasting will fill up the total space and afford a safe support for the overburdened roof of the coal mine, and will allow but little subsiding of the earth above the mine, and any such subsiding will be small and will take place gradually at different times.

In the accompanying drawings is disclosed a concrete example of the process involved'.

Either after the mine has been partly Worked or abandoned or during the mining operation a plurality of drillings or borings l are provided from room 2. The borings l are in the roof while similar borings 3 are provided in the fioor. In these respective borings are placed dynamite or other explosives which are arranged to be set ofta by fuses or any other desired means. These borings are made sufficiently deep for blasting up sufficient rock to fill the hole formed in either the floor or roof, and to also fill approximately half the room 2. Preferably the charges in the first one or two holes are set ofi', and then one or two charges immediately above are set off for blasting up and down the floor and roof, as shown more particularly in Fig. 2. After this has been done one or more charges in the floor are set off, and again one or more in the roof. This alternate setting` oft of the charges is continued for any desired distance, as shown in Fig. 4, for filling room 2 to any desired extent. If it is desired to remove the pillars 4: the room 2 is preferably entirely filled with this blasted rock, (Fig. 1), and then the pillars each side removed, after which the rooms on each side are filled with blasted rock in a similar manner to that just described. If it is desired to remove all the coal during the first mining no pillars of coal are left at all, their place as roof supports being occupied by the blasted rock from the roof and floor,-the excavations of the mine being gradually thus filled (or as nearly so as necessary) as rapidly as mining advances. It Will be evident that if desired the floor and roof may be blasted at the same time, or either the floor or roof may be blasted independent, for filling the entire space. By this arrangement of providing a support for the roof the roof is supported by the usual pillars, and by this auxiliary support. lf it is desired the pillars of coal may be removed leaving nothing but crushed rock for supporting the roof, which roof Will subside but little, and such subsiding will be very slow.

In Figs. 5 and 6 the principle involved in the invention is disclosed as applied to pitching veins Where the vein 5 is at a considerable angle. In a mine of this character an entry 6 is provided for the usual mining car, and from this entry an opening 7 is dug for a short distance into Which opening is placed a chute 8. Chute 8 may be made of timber, metal, or of any other desired material, and is designed to permit the entrance of the Workmen and to present means for directing the mined coal to car 9. The

chute 8 fills the opening 7 so that the Workmen may throT all of the coal in the chute Which Will pass out and be dumped in car 9, while the slate, and other refuse material,

.ing or mined room.

Will be dumped in the bottom of the open- As the coal is dug away from above and it is found that there is not sufficient slate or other refuse matter to provide supporting means for the Workn men part of the roof is blasted down. This acts in a double capacity, namely, as a platform or scaffolding for supporting men, and also as a roof support for preventing the collapsing of the mine. By this arrangement all of the coal may be mined. Heretofore in mining pitching veins all of the coal and slate and other matter mined was removed, but by this arrangement of means and process for carrying out the same nothing is removed except the coal.

The method embodying the invention is aimed to not only protect the miners While at Work, but to protect the surface property, and in addition to permit the removal of all of the coal from the mine. The cost involved is reduced to a minimum by utilizing the crushed rock already in the mine at the place blasted or operated upon.

In old or abandoned mines the method of operation on the floor and roof may be employed for affording ample support for the superimposed strata for holding up the same properly, and also any property on the surface. This method may be used simply as an auxiliary support in old mines for assisting the pillars therein, or may be used as the entire support for the roof of an old mine when it is desired to remove the pillars therefrom.

lVhat I claim is:

l. The method of mining comprising blasting the floor of the mine for partially filling the mine at the point of blasting, and then blasting down a sufficient part of the roof for filling the remaining open space in the mine, the blasted material being allowed to remain where it falls for filling the open space in the mine and the space caused by blasting, for providing supporting means for the roof.

2. The method of mining which comprises the running of gangways along the body of the material to be mined, forming rooms at one side and connected to these gangWays, taking out the material to be mined and packing the refuse in said rooms on the side of the rooms, blasting up part of the fioor of the rooms for filling the space out of which the mined material has been removed, and Which has not been filled by said refuse, and blasting down a sufficient part of the roof for filling the remaining opening in said rooms not filled by the blasting up of the floor and said refuse matter.

3. The method of mining Which comprehends running gangivays along the body of. material to be mined, Working out the material to be mined in proximity to the passagevvays, piling the Waste material in the space from which the mined material has been removed, and blasting down a( suiiicient part of the roof for completely filling the space provided by removing the mined material when taken with the Waste material placed therein.

4. The method of mining which comprehends taking out the material being mined, the erecting of a chute in the opening Jformed by the removal of themined material, the placing of the Waste material in the bottom of the opening provided by the removal of the mined material, discharging the mined material through said chute, and blasting down from the roof a su'licient part thereo'l for iilling the space provided" by the removal of the mined material which is not already filled by the Waste material for providing a roof support.

5; The method of mining Which consists in driving in the vein to be mined, a series of entries for haulage and air Ways, said entries being spaced apart so as to leave pillars heavy enough to sustain their normal share of the superimposed strata, and the Working out of rooms at one side of said entries, placing charges of explosives in the floor and roof of said rooms, and successively discharging the explosives in the floor and roof for filling said rooms with crushed material from the floor and roof for provid- -ing auxiliary supports for the roof.

material to be mined, forming rooms to one side of the gangvvay, and Connecting the rooms to the gangivay, blasting up part of the floor of any of said rooms, and leaving the blasted material in the place Where it falls, and then blasting down a sulicient part of the roof for filling the space immediately above said lrst mentioned blasted material for providing an artificial pillar for supporting the roof.

7. The method of mining which comprehends formingexplosive.receiving `bores in the roof floor of the mine, placing ex` plosive material in each of said bores, exploding the explosive material in part of the bores of the floor, exploding the explosive material in part of the bores of the roof arranged above the explosive material exploded in the floor, and then exploding the explosives in the bores of the fioor and roof alternately until the desired supporting pillar is provided.

S. The method of mining which comprehends the placing of an explosive in the iioor of an abandoned mine, the placing of an explosive in the roof of the mine, and exploding said explosives in any desired sequence, and leaving the matter loosened by said explosives in the place Where it falls for providing a support for the roof of the mine.

In testimony whereof I aiiix my signature in presence of two Witnesses.

WILLIAM GRIFFITH.

Vitnesses Roer. T. LANG, A. L. KrroHIN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

